For a thin film transistor-liquid crystal display (TFT-LCD), the degree of rotation of liquid crystal molecules are varied with variance in the electric field intensity applied to a liquid crystal layer, so that the level of light permeability is controlled to display an image. Generally, a liquid crystal display panel comprises a backlight module assembly, a polarizer, an upper substrate (usually a color filter substrate), a lower substrate (usually an array substrate), and a liquid crystal molecule layer filled in a liquid crystal cell formed with these two substrates. Data lines and gate lines, which intersect each other laterally and longitudinally, are formed on the array substrate, and the data lines and the gate lines surround and define pixel units which are arranged in a matrix. Each of the pixel units comprises a TFT switch element and a pixel electrode. The TFT switch element comprises a gate electrode, a source electrode, a drain electrode and an active layer; the gate electrode is connected to a gate line, the source electrode is connected to a data line, the drain electrode is connected to the gate electrode, and the active layer is formed between the source and drain electrodes and the gate electrode. A common electrode may be further formed on the substrate and acts to form an electric field together with the pixel electrode, and degree of rotation of liquid crystal molecules are controlled by variance in electric field intensity between the common electrode and the pixel electrode. A storage capacitor may be further formed between a storage capacitor line on the TFT array substrate, which is parallel to and located in the same layer as the gate lines, and the pixel electrode and acts to maintain states of the liquid crystal molecules before the next signal arrives.
In an advanced super dimension switch (ADS) technology, a multi-dimensional electric field is formed by an electric field produced at edges of slit electrodes on the same plane and an electric field produced between a layer of the slit electrodes and a layer of a plate-like electrode, so as to allow liquid crystal molecules in all orientations in a liquid crystal cell, which are located directly above the electrode and between the slit electrodes, to be rotated, thereby enhancing the work efficiency of liquid crystals and increasing the transmissive efficiency. The Advanced Super Dimensional Switch technology can improve the picture quality of TFT-LCD products, and has advantages of high resolution, high transmittance, low power consumption, wide viewing angle, high aperture ratio, low chromatic aberration, push Mura-free, and etc.
In the course of manufacturing a TFT array substrate of an ADS mode, production of a pixel electrode layer, a source electrode, a drain electrode and an active layer is usually conducted in a layered manner. Thus, not only thickness of the substrate is increased, but the process flow is cumbersome.